Measuring voltage and current is relatively simple. The challenge grows when the device has to turn those quantities into reliable energy metering, keeping its accuracy over time and integrating with other systems.

In this project, ECK developed an electronic module to measure and track electrical energy consumption. Beyond the measurement itself, the device had to offer a local display, communication with external systems and features to detect abnormal events on the power line.

Component choice starts before the circuit

ECK works as a partner Design House for Alphatech, a component distributor, keeping technical contact to evaluate components and solutions suited to each development.

This relationship matters because choosing a component does not depend only on its datasheet characteristics. Market availability, cost, technical support, documentation and use of the component by other customers at higher volumes also come into the decision.

For this project, the chosen solution was based on the ADE9153A, an IC dedicated to energy metering.

One feature was particularly important for the application: self-calibration.

The calibration challenge in an energy metering module

In an energy meter, errors do not depend only on the converter used. The whole measurement chain affects the result.

Current and voltage transformers, component tolerances, analog circuit gains and the characteristics of the system itself all have to be considered for the measurement to reach the expected accuracy.

In series production, this creates another problem: calibrating each unit individually can require procedures, instruments and production time.

Using a component with self-calibration simplified this step and was one of the deciding factors for the chosen architecture.

Instrumentation-grade transformers

Another point of care was the choice of the elements used to measure voltage and current.

The project used current and voltage transformers designed for metering applications, with known characteristics and curves.

Working with previously characterized measurement elements makes the chain more predictable and makes it easier to develop the complete system, especially when the goal is repeatability across production units.

Planning for future certification

Component selection took into account not only the immediate project requirements but also a possible future need to certify the product.

The chosen metering solution came with documentation related to the standards that apply to energy metering equipment, including references to the IEC 62053 family and EN 50470.

This does not mean that using a given component automatically certifies the final equipment. However, using components designed for this type of application and having the manufacturer’s technical documentation can greatly simplify the work if the product later has to go through a formal certification process.

This is something ECK looks at from the architecture stage: certification is much simpler when its requirements are considered during design, not only after the product is finished.

Local display and user interface

The device also included a Nextion display, allowing the measured quantities to be viewed locally and providing an operator interface without making the main hardware overly complex.

Users could follow the information directly on the device, while the embedded system remained responsible for acquisition, processing and managing the measurements.

Modbus for integration with other systems

Besides the local interface, the module made its data available over Modbus.

This made it possible to integrate the device with supervisory systems, controllers or other data acquisition platforms.

With this communication, the module is no longer just a standalone instrument. Consumption data can be collected periodically and stored, making it possible to follow how the installation behaves over time.

In practice, the device can also be part of a data logging and energy monitoring architecture.

Detecting events and consumption peaks

Another feature implemented was handling of alarms associated with peaks and abnormal power conditions.

Beyond knowing cumulative consumption, it becomes possible to identify that a given event occurred in a specific period.

This information can be useful when investigating problems in machines, processes or electrical installations, correlating an occurrence with how the power supply behaved at that moment.

Engineering beyond the measurement

Developing this module shows that an energy metering system involves decisions that go beyond simply selecting an IC that can measure voltage and current.

It required considering accuracy, calibration, sensors, component availability, user interface, industrial communication, data logging and the possibility of future certification.

Choosing the architecture early on made it possible to bring these features together in a single platform while reducing difficulties that could have appeared later in production and in the product’s evolution.

See other electronic engineering projects developed by ECK.